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Building Insulation FAQ

Q1. What is radiant heat?

Radiant heat is one of the three ways that heat is transferred. Heat always goes cold by natural law hence there are three ways in which heat goes from warm spaces to cold spaces.

  1. Conduction is a direct heat flow through a solid object such as a wall or a ceiling.
  2. Convection is heat movement through air, occurring when air is warmed.
  3. Radiation is the movement of heat rays across air spaces from one warm object to a cooler object. The heat we feel from a wood stove or a quartz space heater is radiant heat.
Q2. What is emissivity?

The emittance of a material refers to its ability to release absorbed heat. Emissivity is express by number between 1 and 1, or 0% to 100%. In general, the more reflective a material is, the lower its emissivity.

Q3. What is a radiant barrier?

A radiant barrier is a material that has an emissivity of 0.1 or less and a reflectivity of 90% or greater (according to ASTM materials testing standards). With that, a radiant barrier can effectively block the transfer of heat.

Moreover, radiant barrier come in sheets with a highly reflective surface on one or both sides, depending on its application.

Q4. How does radiant barrier works? (Cold Climate)

Radiant barrier holds heat in the house, just like wrapping a baked potato in aluminium foils to keep it warm longer by holding the heat in it.

Q5. How does radiant barrier works? (Warm Climate)

Radiant barrier reflects the sun’s heat before it can warm up the insulation in your attic, just like a space suit. Hence when the insulation stays cooler, your house will eventually be cooler.

Q6. What is the different between mass insulation and radiant barrier?

Unlike mass insulation (EG: fiberglass) which only slows down or resists heat transfer, radiant barrier reflects heat.

Q7. Will my roof get hotter when I have radiant barrier in my attic?

Radiant barrier has been used extensively in hot climate country, showing no difference in roof temperatures, as confirmed by field tests.

Q8. Should I remove any old insulation to put up radiant barrier?

You should not as radiant barrier actually makes your present insulation more effective.

Q9. Where do I install radiant barrier?

Radiant barrier can be laid on present insulation like a blanker or stapled under your rafters or crawl space.

Q10. Why should we use Radiant Barrier?

Some studies show that radiant barriers can lower cooling costs 5% – 10% when used in a warm, sunny climate.

Q11. How it is possible by the use of Radiant Barrier can reduce cooling costs?

On a sunny summer day, solar energy is absorbed by the roof thus heating the roof sheathing and causing the underside of the sheathing and the roof framing to become hot. These surface then radiate heat downwards toward the attic floor. By using radiant barrier, the energy flow is reduced thus the attic temperature is also lowered.

Q12. What would be the recommended type of foil for my usage?

In order for us to recommend contact us directly.

Q13. What is the different between single and double sided aluminium foil?

Under similar installation set up, the air space provided by double sided aluminium foil will perform better compared to single sided. Other than that, the physical property of double sided aluminium is also better.

Q14. What is the different between adhesive/glue lamination and extrusion lamination?

Adhesive/glue based lamination will delaminate over the time due to temperature and humidity difference. In contrast, extrusion based lamination is resistant to such delaminating problem.

Q15. What do Fire Retardant (FR) refers to?

Fire retardant does not mean it can’t be burnt. It is classified as FR because our FR products are complied with BS 476: part 6 (fire propagation for products) & Part 7 (Surface spread of flame of products).